Railway traffic controlling system



Oct. 2, 1934. G. w. DAVISON RAILWAY TRAFFIC CONTROLLING SYSTEM Filed Dec. 19, 1951 I 4 m 3 w W m m 1 mm L MW 5n N M? 3 v E 4 OW Q. N v kw m N Z a? Q vm m M mm nrls & J N. MN 3 m 1W3 mm I. Om vv J \HVA 3 1 sm mm k ATTORNEY Patented Oct. 2, 1934 PATENT OFFICE 1,975,134 I RAILWAY TRAFFIC CONTROLLING SYSTEM Gordon W. Davison, Rochester, N. Y., assignor to General Railway Signal Company, Rochester, N. Y.

Application December 19, 1931, Serial No. 582,084

12 Claims.

This invention relates to trafiic controlling systems for railroads, and more particularly pertains to the remote control of power operated track switches in interlocking systems.

The present invention proposes to provide a control system for use with a power operated track switch, in which a switch machine for operating the track switch is controlled in such a manner that an operation of the track switch is prevented from being initiated during the occupied condition of its associated detector track section; and also in which an operation of the track switch already initiated is allowed or caused to be completed even upon the entrance of a train into its associated detector track section, irrespective of contemporaneous control conditions set up by the operator in the tower.

Various'other features, advantages and characteristic functions of the present invention will be in part obvious from the accompanying drawing, and in part pointed out, as the description progresses.

In describing the invention in detail, reference will be made to the accompanying drawing which illustrates in a simplified and diagrammatic manner the circuits and parts of a switch machine control system embodying the present invention, as applied to a single track switch.

With reference to the accompanying drawing, a railroad track switch TS is indicated as being operated by a switch machine SM which may be of any suitable type, as disclosed for example in. the patent to W. K. Howe, No. 1,466,903, dated September 4, 1923. This switchmachine has associated therewith a control relay CR together with normal and reverse contactors N and R respectively for governing the normal and reverse operating circuits of the switch machine motor having an armature A and a field winding F. These relays may be suitably located within the switch machine structure, or may be provided with a separate housing as desired. Inasmuch as these relays serve to govern the operating circuits of the switch machine motor, the usual pole changer contacts and pole changer coils of the switch machine are omitted.

The-switch machine SM is preferably providedwith suitable point detector contacts and associated mechanism, as shown for example in the patent to C. S. Bushnell No. 1,517,236, dated November 25, 1924, which mechanism is employed for controlling the contactors N and R and various other devices such as suitable switch position repeating relays (not shown). The point detec tor contacts include two pair of fixed contacts 5 and 6 together with movable contacts 7 and 8 for controlling the contactors N and R, The movable contact 7 makes contact between the fixed contacts 5 when in normal and mid stroke positions, while the movable contact 8 makes contact between the fixed contacts 6 when in reverse and mid stroke positions. These movable contacts 7. and 8 are jointly operated by the trackswitch TS and the switch machine SM, so as to assume normal or reverse positions when the track switch is in normal or reverse positions and locked by the switch machine, and so as to assume intermediate or mid stroke positions whenever the track switch is being operated by the switch machine SM'or whenever the track switch TS is unlocked.

The control relay GR is preferably of the two position polarized type, that is, its contacts are operated to opposite positions by the application of potential of opposite polarities, and are held in their last operated position by some suitable means such as a magnetic stick type structure or a suitable mechanical toggle device. The contacts 10 and 31 of the control relay-CR. are preferably of the break beyond center type, as the operating circuit for the'control relay CR includes the contact 10 which requires that the operating circuit be completed-until the mechanism of the control relay has been operated sufliciently to allow the toggle device or other means to insure the operation of this contact 10 to the new extreme position. One relay providing these characteristics is shown, for example, in the pending application of J. F. Merkel Ser. No. 536,917, filed May12, 1931. I

The contactors N and R are of the usual tractive type each one of which is provided with two windings, namely, a pick-up winding and a holding winding; These contactors have'the usual characteristics of a tractive type relay device in thatthe degree of energization required to hold their contacts in energized positions is a much smaller value than that requiredto actuate their contacts to picked up positions. Thus, the pickup windingsof the contactors are wound with such a resistance and with the proper number of I turns to cause the contacts to be actuated to energized positions when the pick-up winding of the contactor is energized with the normal voltage of the particular source which provides energy therefor; while the holding windings are wound with such a resistance and number of turns that when the pick-up and holding windings of each of the contactors are all connected in series (four coils inseries) with the same source, then the degree of energization of each contactor is trafic th'ereover and that they are suitably interlocked with the switch machine control either electrically or mechanically, all of which has been omitted for the sake of simplifying the disclosure of the present invention.

A suitable source of electrical energy is located in the tower or at a power station, for supplying energy to the various switches and other traffic controlling devices of the interlocking system. For this purpose a battery BT has been illustrated as supplying energy to" the bus wires 15 and 16 from which energy is taken both at the tower and at the switch machine for the governing of the track switch TS. V

In the tower, switch machine lever SML is provided for governing the application of energy to the polarized circuits for operating the control relay CR and the contactors N'fand R over suitable polarized control circuits.

Although the switch machine control lever SML has been shown as a simple free lever, it is to be understood that it may be of any suitable type known in the railway signalling art, as for example the usual interlocked control lever having mechanical interlocking connecting it with the other devices in the system, or suitable electrical interlocking may be employed in the system. Also, suitable detector locking, approach locking and such other features of interlocking systems may be associated with the control lever SML, as desired, so as to provide adequate signal protection for the operation of trains over the track switch TS all of which has been omitted for convenience,indescribing the present invention.

It is believed that the nature of the invention, its advantages and characteristic features can be best understood with further description being set forth from the standpoint of operation.

Operation With the system in the normal conditions illustrated, where the track switch .TS and switch machine control lever SML are in correspondence, the control relay OR is shunted thereby being protected from the chance application of foreign currents; and similarly, the contactor circuits then connected with the lever are likewise short circuited. For example, the short circuit for-the control relay OR is completed from the negative bus 16, through wires 20 and. 21, contact 22 of lever SML in a normal position, line wire 23, windings of relay CR, wire 24, polar contact 10 of control relay GR in a left hand position, wire 25, back to the negative bus 16. The short circuit for the contactor line circuit is completed from the negative bus 16, through -wires 20 and 26, contact 2'7 ofswitch machine control lever SML in a normal position, line wire 28, front contact 29 of track relay-T, wire 30.,

polar contact 31 of relay CR in a left hand posi.

tion, wires 32 and 33, holding winding 3 of the normal contactor N, wire 34, holding winding 4 of the contactor R, wires 35 and 36, point detector contacts 57, wire 37, pick-up winding 2 of the reverse contactor R, wire 38, back to the negative bus 16.

Whenever the detector track section associated with the track switch TS is unoccupied by a train and the track relay T-is energized, the switch machine SM may be controlled by the lever SML so as to operate the track switch TS to a new position, or back and forth between its opposite positions, as desired. Let us assume that the operator moves the switch machine lever SML to a reverse dotted line position. This causes the application of opposite polarities to the two terminals of the control relay CR thereby causing its contacts to be operated to opposite positions. For example, this circuit is completed from the positive bus 15, through wires 40 and '41, contact 22 of lever SML in a reverse position, line wire 23, windings of control relay CR, wire 24, polar contact 10 of relay GR in a left hand position, wire' 25, to the negative bus 16. The current which flows in this circuit actuates the contacts of the relay CR to righthand positions, and such completion of operation of the contacts is insured as the contact 10 is a break beyond center contact which allows the toggle device or magnetic stick device to positively take efiect to complete the actuation of the contacts to new positions and hold them in such positions. The momentum of the contacts also serves to insure that they are operated to their new positions.

As soon as the contacts of the control relay CR assume their new positions, the windings of the control relay are shunted through a circuit from the positive bus 15, through wires 40 and 41, line wire 23, windings of control relay CR, wire 24, polar contact 10 of relay CR in a right hand position, wires 42 and 43, back to the positive bus 15.

With the contacts of the control relay CR now in correspondence with the contacts of the switch machine lever SML, an energizing circuit is completed for the pick-up winding 2 of the reverse contactor R, from the positive bus 15, through wires 40 and 44, contact 27 of switch machine lever SML in a reverse position, line wire 28, front contact 29 of track relay T, wire 30, polar contact 31 of control relay CR in a right hand posi tion, wires 45 and 36, point detector contacts 5-7, wire 37, pick-up winding 2 of the reverse contactor R, wire 38, to the negative bus 16.

The current which flows in this circuit is suiiicient to cause thecontacts of the reverse contactor R to be actuated to picked up or energized positions. The closure of its front contact causes current to be supplied to the armature A and field winding F from the positive bus 15, through wires 43, 46 and 47, front contact 48 of reverse contactor R, field winding F, back contact 49 of normal contactor N, wires 50 and 51, windings of the armature A, wire 52, to the negative bus 16. The current which flows in this reverse operating circuit causes the armature A to revolve in a reverse direction for the operation of the track switch TS through the medium of the switch Ill) machine mechanism to a reverse locked position. i. g,

In other words, the switch machine, when operated by the motor, unlocks the track switch TS, operates it to the new position and again looks it all in the usual manner as specifically described in the above'mentioned patent to W. K. Howe, No. 1,466,963, dated September 4, 1923.

'During the operation of the switch machine SM the movable contacts '7 and 8 assume mid stroke positions which completes a holding circuit for both of the contactors, but as the reverse contactor is the only one which has been energized, then the contacts of the normal contactor N remain in deenergized retracted positions. Also, this holding circuit, completed with the track switch and switch machine in mid stroke condisuch operation is merely the converse tions, is effective only when the track relay T of the detector track section is deenergized.

I Assuming for example that the track relay T is deenergized due to-the entrance of a train immediately following the initiation of the switch machine into operation and after the contacts 7 and 8 have assumed midstroke positions, then the holding circuit is completed from the positive bus through wire 53, pick-up winding 1 of the normal contactor N, wire 54, point detector contacts 6-8, wires 55 and 33, holding winding 3 of the normal contactor N, wire 34, holding winding 4 of the reverse contactor R, wires and 36, point detector contacts 57, wire- 37, pick-up winding 2 of the reverse contactor R, wire 38, to the negative bus 16. As previously mentioned, the current which flows in this circuit is of suificient value to maintain the contact 48 of reverse contactor R in an energized position, but is of insufficient value to actuate the contact 49 of normal contactor N to an energized position.

' It isobvious that so long as the contact 29 of the track relay T is closed that this holding circuit is not effective as the pick-up and holding windings of the normal contactor N and the holding winding of the reverse contactor R are short circuited through a circuit from the positive bus 15, through wires and 44, contact 27 of switch machine lever SML in a reverse position, line wire 28, front contact 29 of the track relay '1', wire 30, polar contact 31 of control relay CR in a right hand position, wires and 35, holding winding 4 of the reverse contactor R, wire 34,

"3'5 holding winding 3 of the normal contactor N,

wires 33 and 55, point detector contacts 6-8,

wire 54, pick-up winding 1 of the normal con- .tactor N, wire 53, back to the positive bus 15.

Thus, the reverse contactor R is maintained d energized for completing the reverse operation of the track switch either through its pick-up winding if the detector track section is not occupied, or through its pick-up and holding windings i'f the detector track section becomes occupied, but in either case, the operation is, insuredof completion. It is further noted, that the holding circuit is completed independently of the contact of the control relay CR, therefore, should the control relay CR be accidentally or otherwise operated to a new position subsequent to the deenergization of the track relay T and during mid stroke operating conditions,,any operation already initiated will be completed.

When the switch machine has completed the reverse operation of the track switch TS, as above described, the movable contacts 7 and 8 are operated to reverse positions which opens the pickup and holding circuits for the reverse contactor R.- Thus, the switch machine motor is brought to a condition of rest. f

It is believed that the. operations involved in operating the track switch TS from a reverse position to a normal position will be understood by analogy to the description already given, as

of the operation already described. V

Let us assume that the system is in the normal conditions illustrated, and that a train is on the detector track section deenergizing the track relay T, thecontrol relay CR may be operated in anticipation of the next operation dependent of course upon the automatic signalling associated therewith in accordance with the usual practices, but the-switch machine cannot be operated inasmuch as front contact 29 is open and the pickup circuit for the pick-up winding of the reverse contactor cannot be-completed. Thuathe track switch is adequately protected against initiating a new operation during the occupied condition of its'detector track circuit.v

Although the operating circuits of the switch machine including the armature A and field winding have been shown in a simplified and diagrammatic manner, it is to be understood that suitable blow-out means may be associated with their controlling contacts, and that suitable overload protection may be provided in connection therewith. Also, if overload protection is provided, it may be of any suitable type as shown for.

example in the application of Hoppe and Swanton, Ser. No. 474,758, filed August 12, 1930, which issued as Patent No. 1,877,876, on Sept. 20, 1932 all of which is considered as preferably employed in actual practice, but which has been omitted to simplify the disclosure for an understanding of the present invention.

Thus, a control circuit for a power operated track switch has been shown and described which permits the operation of a track switch, as may be desired, by the operator and in accordance with the automatic signalling system employed in connection therewith, but with adequate protection for preventing the initiation of an operation of the track switch during the occupied condition of the detector track section, and also to provide that an operation initiated just prior to the entrance of a train into the detector track section may be insured of completion.

Having described a switch machine control system as one specific embodiment of the present invention, it is desired to be understood that this form is selected to facilitate in the disclosure of the invention rather than to limit the number of forms which it may assume; and, it is to be further understood that various modifications, adaptations and alterations may be applied to the specific form shown to meet the requirements of practice, without in any manner departing from the spirit or scope of the present invention except as limited by the appended claims.

What I claim is:-

1. In combination; a railroad track switch; a switch machine for operating said track switch; point detector contacts jointly operated by said track switch and said switch machine; normal and reverse contactors for governing the operating circuits of said switch machine, each of said contactors having pick-up and holding windings; a detector track section associated with said track switch; means for energizing said pick-up windings of either said normal or said'reversecontactor only when said detector track section is unoccupied if said switch machine is 'in an extreme position; and means for energizing said pick-up and holding windings of said normal and reverse contactors all in series when said detector track section is occupied if said switch machine is in operation, said means including said point detector contacts.

2. In a control system for railroad track switches; a switch machine for operating -a track switch; point detector contacts having normal,

reverse and mid stroke positions; normal and; re-

verse contactors each having pick-up and holding-windings, each being initially actuated only when energized to one degree, and "each being maintained actuated when energized to another degree, said another degree being less than said one degree; a detector track section associated with said track switch; a control relay having a contact operable to opposite extreme positions;

means manually governing said control relay; a circuit for said pick-up winding of said normal contactor closed when said contact of said con- \trol relay is out of correspondence with said point detector contacts in reverse or mid stroke positions and said detector track section is unoccupied, whereby said normal contactor is energized to said. one degree; a circuit for said pick-up winding of said reverse contactor closed when said contact of said control relay is out of correspondence with said point detector contacts in normal or mid stroke positions and said detector track section is unoccupied, whereby said reverse pontactor is energized to said one degree; a circuit for said pick-up and holding windings of said normal and reverse contactors all connected in series, whereby said contactor is energized to said another degree, said circuit being closed only if said point detector contacts are in mid stroke positions and said detector'track section is occupied; and a normal and a reverse operating circuit for said switch machine governed by said normal and reverse contactors respectively. 3. In a trafiic controlling system for railroads; a track switch; a switch machine for operating said track switch; a detector track circuit associated with said track switch; a normal and a reverse operating circuit for said switch machine; a normal and a reverse contactor, each for closing the corresponding one of said operating circuits; a control lever having normal and reverse positions; a pick-up circuit for each contactor, the corresponding circuit being closed when said ilever is operated to normal or reverse positions out of correspondence with said track switch; point detector means operated by said track switch for opening said pick-up circuits when said track switch is in correspondence with said control lever; means for opening said pick-up circuits when said detector track section is occupied by a train; and holding circuits for said normal and reverse contactors, said holding circuits being energized if said detector track circuit becomes occupied before the completion of an operation and remaining energized only until said switch machine has completed said operation or said detector track circuit has become unoccupied. 4. In a tranic controlling system for railroads;

"a track switch; a switch machine for operating said track switch; point detector contacts operable to normal, reverse and mid stroke positions; a control relay; a control lever for operating said control relay; normal and reverse contactors for closing normal and reverse operating circuits of said switch machine; pick-up circuits for said normal and reverse contactors respectively closed when said control lever and said control relay are both out of correspondence with said point detector contacts; and holding circuits for said normal and reverse contactors made effective by said point detector contacts in mid stroke positions if a pick-up circuit is opened prior to the completion of an operation of said switch machine.

5. In combination, a railroad track switch, a detector track section associated with said track switch, a switch machine for operating said track switch to normalor reverse positions, normal and reverse contactors for respectively causing normal and reverse operation of said switch machine, means manually operable to energize either the normal or the reverse contactor to cause the corresponding operation, means rendering said manually operable means ineffective whenever said detector track section is occupied, and means automatically'operable to energize said normal and reverse contactors only when said manually operable means is rendered ineffective during an operation of said switch machine.

6. In combination; a railroad track switch; a switch machine for operating said track switch; point detector contacts jointly operated by said track switch and said switch machine; normal and reverse contactors for governing the operating circuits of said switch machine; a detector track section associated with said track switch; pick-up circuits for said normal and reverse contactors capable of being closed only when said detector track section is unoccupied; and holding circuits for said normal and reverse contactors capable of being energized only when said detector track section is occupied and said switch machine is in operation.

7. In combination; a railroad track switch; a switch machine for operating said track switch; point detector contacts jointly operated by-said. track switch and said switch machine; normal and reverse contactors for governing the operating circuits of said switch machine; a detector track section associated with said track switch; pick-up circuits for said normal and reverse contactors capable of being closed only when said detector track section is unoccupied; a holding circuit for said normal and reverse contactors capable of being energized only when said detector track section is occupied and said switch machine is in operation; and current limiting means in said holding circuit, whereby said holding circuit is effective only when said normal or reverse contactor has been energized by its pickup circuit. I

8. In a control system for railroad track switches; a switch machine for operating a track switch; a detector track section associated with the track switch and provided with a track relay; a polar control relay having a two position contact; a control lever; positive and negative bus wires; a source of electrical potential for supplying energy to said bus wires; circuit means including said two position contact for connecting one terminal of said control relay to said bus wires alternately; circuit means including said control lever for connecting the other terminal of said control relay to said bus wires alternatel ly; and means including said track relay and said control relay for governing the operation of said switch machine.

9. In a control system for railroad track switches; a switch machine for operating a track switch; a detector track section associated with the track switch and provided with a track relay; a polar control relay having two position contacts; a control lever; positive and negative bus wires; a source of electrical potential for supplying energy to said bus wires; circuit means including one of said two position contacts for connecting one terminal of said control relay to said bus wires alternately; circuit means including said control lever for connecting the other terminal of said control relay to said bus wires alternately; a normal contactor having one terminal connected to said positive bus wire; a reverse contactor having one terminal connected to said negative bus wire; a control line wire connected through a front contact of said track relay; circuit means including another of said two position contacts for connecting one end of said control line wire to the other terminal of each of said normal and reverse contactors alternately; circuit means including said control lever for connecting the opposite end of said control line wire to said bus wires alternately; normal and reverse operating circuits for said switch machine closed by said normal and reverse contactors respectively; and means maintaining said contactors energized during an operation of said switch machine if said track relay opens said control line wire during such operation.

10. In combination, a track switch; a switch machine for operating said track switch and having a normal, a reverse and an intermediate position; a normal relay having two windings and for operating said switch machine to the normal position; a reverse relay for operating said switch machine to the reverse position and having two windings; means for applying a source or" current to one winding of said normal relay capable of picking up such normal relay, or applying said source to one winding of said reverse relay capable of picking up such reverse relay; traffic controlled means for preventing such application of such source to such windings when there is a train approaching said track switch; and a circuit for connecting all of said windings series if said switch machine is then assuming an intermediate position, said relays being constructed not to pick up but to hold up when already up if all of said windings are connected in series across said source.

11. In combination, a track switch; a switch machine for operating said track switch and having a normal, a reverse and an intermediate position; a normal relay having two windings and for operating said switch machine to the normal position; a reverse relay for operating said switch machine to the reverse position and having two windings; means for applying a source of current to one winding of said normal relay capable of picking up such normal relay, or applying said source; and means for breaking said circuit when said switch machine has been operated to its normal or its reverse position.

' 12. In combination, a track switch; a switch machine for operating said track switch and having a normal, a reverse and an intermediate position; a normal relay having two windings and for operating said switch machine to the normal position; a reverse relay for operating said switch machine to the reverse position and having two windings; manually operable means for applying a source of current to one winding of said normal relay capable of picking up such normal relay, or applying said source to one winding of said reverse relay capable of picking up such reverse relay; trains controlled means for preventing such application of such source to such windings when there is a train approaching said track switch; a circuit independent of said manual and said traffic controlled means for connecting all of said windings in series if said switch machine is then assuming an intermediate position, said relays being constructed not to pick up but to hold up when already up if all of said windings are connected in series across said source; and means for breaking said circuit when said switch machine has been operated to its normal or its reverse position.

GORDON W. DAVISON. 

